In multicolor printing processes such as full-color printing processes, a plurality of master plates are prepared for different colors such as cyan, magenta and yellow through the process of color separation, and a printing process is repeated for each of the master plates or, in other words, the prints by the different master plates are superimposed one over another.
When a multicolor printing process is to be carried out according to the principle of superimposition, the master plate for each of the colors is prepared, and the printing process is repeated by mounting each of the master plates in turn, so that the master plate is required to be changed each time the printing process with one of the master plates it completed.
According to such a printing process based on the principle of superimposition, each print must be made on an identical region of the print object such as printing paper. Otherwise, misregistration occurs, and the print result will become unsatisfactory.
To ensure that each print is made on an identical region of the print object such as printing paper, not only a high level of accuracy must be achieved with regard to the positioning of the print object such as printing paper relative to each of the stencil master plates used for the stencil printing or, in other words, the accuracy of the registration of the print object relative to the stencil printing device must be raised to a high level, but also each stencil master plate must be accurately mounted on the master plate mounting unit of the stencil printing device.
However, such a positioning process cannot be easily achieved in the cases of simple stencil printing devices of the printing press type for home and offices use, and the registration accuracy is further compounded by the error in the mounting position of the stencil master plate. Therefore, according to such stencil printing devices, it is extremely difficult to achieve good results by using the printing process based on the principle of superimposition.